At that last step of the install....
you've got to delete the install.php, createtable.php and altertable scripts from your server before you can follow that link to create the initial user... or else you'll get an error.
The instructions to do so are there... but recently I set up a new install and missed it myself and it puzzled me... so I think it's easy enough to overlook.
The last step of install... after you delete those files... you go to URLtoThreadsInstal/newuser.php and create a user.
This first user you create will be "god" LOL and the first Admin on the account.
Once you do that, they you can visit your forums, login THEN you will be able to visit the admin section.
Hope that helps ya a bit more... or at least keeps you plugging along in the right direction. <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" />
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